Trying to login to my Apple ID account using itunes, App Store, iCloud. Each application freezes after entering password. This began after installing the new OS X 10.11 - El Capitan.

I'm currently using a MacBook Pro 15' (Mid -2010). Never had this problem with OS X Yosemite. Not sure if it has anything to do with the Keychain. Anyone having the similar problems?? Any help will be gladly appreciated..!!!

Previously, I was never able to login to use iMessage from my desktop Mac, but basically ignored the problem (used my iphone). After El Capitan, I was not able to access iTunes or iCloud at all.

I did notice that I was missing a serial number on my computer (from Finder, go to About This Mac). Somehow my serial number got wiped when I took my Mac in for a hard drive exchage (recalled under warranty).

This webpage showed me how to reinitialize the serial number (etched onto the footplate of the Mac chassis). It's moderate difficulty, but not impossible. The trickiest part was getting disk utility to actually burn the Blank Board Serializer to CD. After that, very simple and after restart, everything works!

Previously, I was never able to login to use iMessage from my desktop Mac, but basically ignored the problem (used my iphone). After El Capitan, I was not able to access iTunes or iCloud at all.

I did notice that I was missing a serial number on my computer (from Finder, go to About This Mac). Somehow my serial number got wiped when I took my Mac in for a hard drive exchage (recalled under warranty).

This webpage showed me how to reinitialize the serial number (etched onto the footplate of the Mac chassis). It's moderate difficulty, but not impossible. The trickiest part was getting disk utility to actually burn the Blank Board Serializer to CD. After that, very simple and after restart, everything works!

I did everything correct up until i missed one character on my serial number. Now I need to find a way to rewrite the correct serial number or erase and enter the correct serial number. Anyone know how to rewrite the Serial number again...???

I did everything correct up until i missed one character on my serial number. Now I need to find a way to rewrite the correct serial number or erase and enter the correct serial number. Anyone know how to rewrite the Serial number again...???

Click to expand...

Wow, you were so close to the finish line!

Sorry, I have no idea how to blank out the serial number again. I would back up your computer, may need a motherboard reset.

Previously, I was never able to login to use iMessage from my desktop Mac, but basically ignored the problem (used my iphone). After El Capitan, I was not able to access iTunes or iCloud at all.

I did notice that I was missing a serial number on my computer (from Finder, go to About This Mac). Somehow my serial number got wiped when I took my Mac in for a hard drive exchage (recalled under warranty).

This webpage showed me how to reinitialize the serial number (etched onto the footplate of the Mac chassis). It's moderate difficulty, but not impossible. The trickiest part was getting disk utility to actually burn the Blank Board Serializer to CD. After that, very simple and after restart, everything works!

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